Vaccines That Protect Against STIs — Have You Had Them?

When most people think about STI prevention, they think about condoms, regular testing, and open communication with partners. All of those matter. But there's another layer of protection that doesn't get nearly enough attention — and it's one of the most effective preventive tools available: vaccination.

For a small number of STIs, vaccines exist that can eliminate or significantly reduce the risk of infection entirely. Here's what they are, who they're for, and whether you've had them.

HPV Vaccine

Human papillomavirus is the most common STI globally — and it's the one most people associate with vaccination. The HPV vaccine protects against the strains most likely to cause cancer (particularly HPV-16 and HPV-18, which together account for the majority of HPV-related cancers) as well as strains associated with genital warts.

HPV is linked to six different cancers — cervical, anal, oropharyngeal, vaginal, vulvar, and penile. Vaccination before exposure to these strains provides strong protection against all of them.

The vaccine is most effective when given before first sexual activity — which is why it's typically offered to adolescents in national vaccination programmes. However, it can still provide meaningful protection when given to adults who haven't yet been exposed to the strains it covers.

In many countries, catch-up vaccination is available for older age groups. In several places, gay and bisexual men can access the HPV vaccine through sexual health clinics regardless of age — because their risk of HPV-related anal cancer remains elevated throughout life.

If you're unsure whether you've been vaccinated or whether you're eligible for catch-up vaccination, a healthcare provider or sexual health clinic can advise.

Hepatitis B Vaccine

Hepatitis B is a sexually transmitted infection that can cause serious liver complications — including cirrhosis and liver cancer — when it becomes chronic. It is significantly more transmissible than HIV through sexual contact.

The Hepatitis B vaccine is highly effective and provides long-lasting protection. It is typically given as a two or three-dose course, depending on the formulation used.

In many countries, Hepatitis B vaccination is now included in routine childhood immunisation schedules — meaning many younger people are already vaccinated. However, if you were born before Hepatitis B vaccination was routine in your country, or if you're unsure of your vaccination status, a blood test can check whether you have immunity.

For sexually active adults — particularly those with multiple partners or in higher-risk groups — Hepatitis B vaccination is strongly recommended if not already immune.

Hepatitis A Vaccine

Hepatitis A is not sexually transmitted in the same way as Hepatitis B — it spreads primarily through contaminated food or water — but it can be transmitted through certain sexual practices, particularly oral-anal contact.

The Hepatitis A vaccine is highly effective and provides long-lasting protection after a two-dose course. For sexually active gay and bisexual men especially, vaccination against Hepatitis A is recommended by major public health bodies including the CDC and WHO.

Unlike Hepatitis B, Hepatitis A infection almost always resolves on its own — but it can cause significant illness, including prolonged fatigue and liver inflammation, for weeks or months. Vaccination removes that risk entirely.

Mpox Vaccine

Since the 2022 global mpox outbreak, vaccination against mpox has become part of the sexual health conversation — particularly for gay and bisexual men and others at higher risk.

The JYNNEOS vaccine (also known as Imvamune or Imvanex) is effective against mpox and is typically given as a two-dose course. It is recommended for people at higher ongoing risk of exposure.

Availability varies significantly by country. In some places it's accessible through sexual health clinics or public health programmes; in others it remains limited. If you're in a higher-risk group and haven't been vaccinated, it's worth checking current availability in your area.

What about HIV — is there a vaccine?

No. Despite decades of research, there is currently no approved vaccine against HIV. Prevention relies on other tools — PrEP for ongoing risk reduction, PEP for post-exposure emergency prevention, condoms, and regular testing.

This makes HIV the significant exception in the STI prevention toolkit — a high-priority infection for which vaccination is not yet an option.

Checking your vaccination status

Many people aren't certain which vaccines they've received — particularly if they were vaccinated in childhood or in another country. A healthcare provider can review your vaccination history and order blood tests to check immunity for Hepatitis A and B specifically.

For HPV, there's no reliable blood test to check immunity in adults — the most practical approach is to discuss your history with a healthcare provider and consider catch-up vaccination if there's uncertainty.

Vaccination and regular testing — how they work together

Vaccination removes certain risks entirely — but it doesn't replace the need for regular STI testing. The infections that have vaccines represent only a fraction of the STI landscape. Chlamydia, gonorrhea, syphilis, HIV, herpes, and others are not vaccine-preventable — and most of them are asymptomatic.

Regular testing remains the foundation of proactive sexual health care, alongside vaccination where it's available.

CLEAR's at-home Ship Kit covers comprehensive STI screening — including HIV, chlamydia, gonorrhea, syphilis, and hepatitis B and C — using PCR-based analysis in a certified medical laboratory, with results delivered privately within 48 hours.

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• Bottom line

Vaccines against HPV, Hepatitis A, Hepatitis B, and mpox represent some of the most effective sexual health interventions available. If you haven't had them — or aren't sure — that's worth finding out. Prevention that works before exposure is always the simplest kind. 😊

The information in this article is intended for general educational purposes only and does not constitute medical advice. Please consult a qualified healthcare professional for personal medical guidance.